Liquid light switch bridges the gap between light and electricity,

Researchers from the University of Cambridge have built a miniature electro-optical switch which can change the spin of a liquid form of light by applying electric fields. Their results, published in the journal Nature Materials, demonstrate how to bridge the gap between light and electricity, which could enable the development of ever faster and smaller electronic.

The University of Cambridge researchers, led by Professor Jeremy Baumberg from the NanoPhotonics Centre, in collaboration with researchers from Mexico and Greece, have built a switch which utilises a new state of matter called a Polariton Bose-Einstein condensate in order to mix electric and optical signals, while using miniscule amounts of energy.

condensates are generated by trapping light between mirrors spaced only a few millionths of a metre apart, and letting it interact with thin slabs of semiconductor material.This creates a half-light, half-matter mixture known as a polariton.

“The polariton switch unifies the best properties of electronics and optics into one tiny device that can deliver at very high speeds while using minimal amounts of power,” said the paper’s lead author Dr Alexander Dreismann from Cambridge’s Cavendish Laboratory.

“We have made a field-effect light switch that can bridge the gap between optics and electronics,” said co-author Dr Hamid Ohadi, also from the Cavendish Laboratory. “We’re reaching the limits of how small we can make transistors, and electronics based on liquid light could be a way of increasing the power and efficiency of the electronics we rely on.”